feat(心跳): 添加游戏客户端心跳处理逻辑

实现游戏客户端心跳消息的生成和发送功能，确保客户端与服务端保持连接

Author: AlianBlank

GameFrameX.Hotfix/StartUp/AppStartUpHotfixGameByDiscoveryCenter.cs

@@ -52,4 +52,17 @@ protected override void GameAppClientOnConnected()
         };
         Send(reqRegisterServer);
     }
+
+    readonly ReqActorHeartBeat _reqActorHeartBeat = new ReqActorHeartBeat();
+
+    protected override MessageObject GameAppClientOnHeartBeat()
+    {
+        _reqActorHeartBeat.Timestamp = TimeHelper.UnixTimeMilliseconds();
+        _reqActorHeartBeat.UpdateUniqueId();
+        return _reqActorHeartBeat;
+    }
+
+    protected override void GameAppClientOnMessage(MessageObject message)
+    {
+    }
 }